Delayed hemolytic transfusion reaction occurred in a 74-year-old woman
after coronary bypass, Antibodies were not detected during preoperati
ve screening but did appear late after exposure to Jk(b)-positive red
blood cells, probably as an anamnestic response to previous exposure d
uring childbirth or remote transfusion. The incidence, pathophysiology
, clinical presentation, diagnosis, and management of this syndrome ar
e discussed.